Wash and pat dry your chicken breasts - cut into halves length wise and place inside of a plastic bag and with a meat mallet pound to 1/4 thickness.
Prepare in a large bowl the egg and 3 tbsp water - whisking , in a plate add your bread crumbs and dried oregano - these will be your dredging points.
In a large skillet heat 2 tsps olive oil add onions, garlic and mushrooms and cook till mushrooms have a golden brown appearance. Take out of skillet and set aside.
Take chicken one piece at a time and dredge through the egg wash and then into the bread crumbs, Placing 1 tbsp of olive oil into skillet add your coated chicken breasts and brown both sides over medium high heat. Return Mushroom mixture back to skillet and add the marsala. Cover and cook over low heat for 30 minutes. Your chicken should be done and you should have a nice thickened gravy - serve over angel hair pasta and add some grated cheese if you like.